AC re-charging problem


adsm08

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I am now thinking this is what happened. Is there something in the process of adding refrigerant that could cause a leak in a system that was previously holding a vacuum?
The only things I can think of are having a fitting on wrong, or loose connections at the hoses. I have to stop and check my gauges every time I use them because the nuts works loose.
 


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Denisefwd93

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Dye is mixed with the oil and travels through the system it won't hurt, it leaves a trace, UV fluorescent is the current technology.

No vacuum means you have a leak I would scrutinize your hose connections,the hose manifold connections, the adapter valves all the o-rings and connectors on the old system also.

you can dehydrate the accumulator somwhat, the longer you leave the vacuum pump on a non leaking system the more it will remove moisture. overnight is good. I didn't change the one on my truck and it's how many old years old? New evaporator, new condenser, new hoses,


(red dye, old school)
 

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The only things I can think of are having a fitting on wrong, or loose connections at the hoses. I have to stop and check my gauges every time I use them because the nuts works loose.
Ok, thanks for responding. Other than checking the pressure this morning and trying to pull a vacuum I haven't been out to dig into it yet. Been stalling on going back outside but I'll check all the connections and torque on the bolts and see if I can find where oil may have leaked out. If I don't see anything obvious I'll probably pull the condensor.

Edit: I'll check the guages too. Like I said, it was missing a cap and later the correct adapter for the new style r134a can, but I got those issues resolved before proceeding.
 

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Dye is mixed with the oil and travels through the system it won't hurt, it leaves a trace, UV fluorescent is the current technology.

No vacuum means you have a leak I would scrutinize your hose connections,the hose manifold connections, the adapter valves all the o-rings and connectors on the old system also.

you can dehydrate the accumulator somwhat, the longer you leave the vacuum pump on a non leaking system the more it will remove moisture. overnight is good. I didn't change the one on my truck and it's how many old years old? New evaporator, new condenser, new hoses,


(red dye, old school)
Thanks. I did notice some of that yellow fluorescent stuff so maybe it's already in there (with the oil). I'll give the whole thing a good inspection here in a little bit. Appreciate the help.
 

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you can dehydrate the accumulator somewhat,
We found we got best results leaving the vacuum pump on, and the engine running for an hour. Heat plus suction helps get that water to boil off.
 

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Update: I checked all the connections and everything easily visible- didn't check the evaporator body- and found nothing to indicate a leak. Removed the Condensor and didn't find any oil/dye on the outside. Connected everything back up, then disconnected both spring locks on the low side. Both seemed to be connected as I had to use a spring-lock tool to get them off. Oiled them up again and snapped them closed. For the hell of it I hooked up the vacuum again and now it's showing vacuum.

27674


So I started up the engine and let it get up to operating temperature and am running the vacuum. Will keep running it for a few hours probably. Don't really understand what is going on but at least it doesn't appear to be a faulty component and was possibly a connection. Will update later.

-------

Also, for any DIY-er who might use the Autozone AC Gauge Set, the included instructions tell you to hook the red hose up to the low side and blue to the high side. This is incorrect. Blue goes to blue goes to blue, and the same for red. I had to spend some time making sure this wasn't correct before I even could get started a couple days ago.

27675
 

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It's easy to get messed up. you basically have three valves on each line connecting to the system, the manifold valve, connector valves, and the actual service valve on the system,

the hose adapter valves aren't just quick connects, they're also designed as a safety feature to prevent escaping refrigerant and ... frozen fingers. It's very possible they weren't properly seated, you could put a few ounces in as a holding charge if you're not under a time crunch, leave it for a day or two see if it holds. If it's good, do another evacuation, if you're using 14 oz cans warm them up to with warm water turn them upside down connect to the yellow hose, purge the hose, open the red valve dump it into the high side, the low side gauge will slowly rise to an equal pressure, 2 warmed up cans should go right into the system without any trouble!
 
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avid

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It's easy to get messed up. you basically have three valves on each line connecting to the system, the manifold valve, connector valves, and the actual service valve on the system,

the hose adapter valves aren't just quick connects, they're also designed as a safety feature to prevent escaping refrigerant and ... frozen fingers. It's very possible they weren't properly seated, you could put a few ounces in as a holding charge if you're not under a time crunch, leave it for a day or two see if it holds. If it's good, do another evacuation, if you're using 14 oz cans warm them up to with warm water turn them upside down connect to the yellow hose, purge the hose, open the red valve dump it into the high side, the low side gauge will slowly rise to an equal pressure, 2 warmed up cans should go right into the system without any trouble!
Thanks for the tips.

After posting last night, when I went back out to check on the vacuum I was messing with the low pressure hose disconnect's fit on the Low Pressure Valve and the vacuum instantly dropped from -28Hg to -10Hg and stayed there. So I'm not sure what the problem is, but I no longer trust the integrity of the gauges or vacuum. I packed up the gauge set and vacuum and returned them to Autozone. I'm going to try a different set of loaner tools from another place, though I suspect they all carry the same Harbor Freight quality loaner tools. Maybe I can find one that has been a little less abused, and maybe that will make it easier to pinpoint the problem.
 

Denisefwd93

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If you disturb any thing when it'st under a vacuum it'll quickly jump up, from what you're saying, I would have put a holding charge in
 
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If you disturb any thing when it'st under a vacuum it'll quickly jump up, from what you're saying, I would have put a holding charge in
This was like I put my hand on the the disconnect and moved my hand a little to make sure it was well-seated and then it jumped. And then I could never get it to pull more than -10Hg. I returned that gauge set and vacuum pump and got different ones that look to be in a little better condition. Maybe, hopefully, that will make a difference. I did get some more refrigerant so I will try to put in a holding charge if I get the gauge set to where I'm satisfied it's connecting well and working properly. The truck is down at the moment regardless while I'm waiting for a rear parking brake cable to arrive so I can finish the rear brake shoes/drums. Thanks for all the advice.
 

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Found a leak where the low pressure line connects to the Condensor. Actually saw the oil spraying out between the joint where the connection is made. This is a metal-to-metal connection with the line having a short tube and O-ring, but the connection design seems unnecessarily tenuous. I removed both and there doesn't appear to be any damage. It's just that there's very, very little snugness in the connection with a single o-ring fitting into a bevel on the condensor. Anyone have any suggestions here? Has anyone ever tried using two o-rings on this particular connection? Or is there a thicker than normal o-ring I could use? Other ideas?

The low pressure line is the silver one and the condensor connection is painted black.

27757
 

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Pressure switches I believe use a standard r134 acme 3/8 thread and a larger o-ring. I can't tell by the picture is this the line coming off the compressor into the condenser? or from the condenser into the evaporator? I'm thinking it's probably the high pressure switch which are pretty cheap to get as a replacement, even hose set was/is under $100,. if you look you will notice that it also has a depressor for the Schrader valve that is on the hose, the high pressure switch has to have pressure against it otherwise the system won't run and you would have to jump it out.
 

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Pressure switches I believe use a standard r134 acme 3/8 thread and a larger o-ring. I can't tell by the picture is this the line coming off the compressor into the condenser? or from the condenser into the evaporator? I'm thinking it's probably the high pressure switch which are pretty cheap to get as a replacement, even hose set was/is under $100,. if you look you will notice that it also has a depressor for the Schrader valve that is on the hose, the high pressure switch has to have pressure against it otherwise the system won't run and you would have to jump it out.
This is the condensor to evaporator hose. The other connection seemed to be fine- at least it wasn't blowing oil. All the parts are new (from Rock Auto) but none of them are motorcraft. You can see the little indented area that receives the o-ring. But either it's too large or the o-ring is too small because the two parts bolt together without compressing the o-ring at all.

27758


Edit: I did put on a second o-ring to see how it felt and that seemed a lot better. The two metal flanges still easily pressed together. But using two o-rings seems a little dicey. Maybe though a fatter single o-ring would work.
 
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Denisefwd93

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I never saw a connection like that one but it is all about the o-ring, get right one and you should be okay, I think it's called a captive o-ring. that is also the orifice line isn't it? maybe they just gave it the wrong o-ring! Sillier things have happened.


Last night checked my system, first time since last summer, I changed all the hoses, evaporator and the condenser but we kept the old compressor which I think has a very small leak as the sniffer beeped one time when I was looking for leaks. The thing I hate right now is the power steering pump and hoses all leaking all over the place, fast enough. It has to be topped off every month or so but not enough to aggravate me to get it fixed and I have the hoses on the shelf.
 
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Lot of things to update here but the short story is I finally have AC.

I tried to locate a fatter o-ring both online and at a couple auto parts stores with no luck. Thought I'd look through the bag of o-rings I ordered along with the parts (didn't realize they all would come with o-rings already) and didn't see any that looked fatter. As I was putting them away though I did notice a fatter one. I presume it was possibly one that was included with the condensor that got mixed in with the others. When I was preparing parts to install I just threw all the o-rings in with the package I had ordered, not thinking they might be specialized (other than the obvious different sizes). Here's a photo showing the difference. I have 20 or so of the narrow o-rings of this size but only one fat one. Why the manufacturer makes this fitting different is beyond me.

27919


I re-installed the condensor and low-pressure hose (for the third time) and hooked up the vacuum again. It seemed to be working so got the truck up to operating temperature and left the vacuum running for an hour or so. When I went to disconnect the manifold gauge from the low pressure valve the low pressure valve was making a hissing noise as if it was leaking. I connected up the gauge again and checked pressure and it seemed to be ok, but when I disconnected it again the valve again hissed a little.

I had seen a video of a guy demonstrating an AC fill and he said that the schrader valves can get bent from the manifold gauge couplings. So I wondered if that's what happened. I happened to have a Schrader Valve replacement kit that the idiots at Autozone convinced me to buy, so I thought I would try to swap out the valve quick. Well, it was the wrong size. Yes, even though I asked if all Schrader valves for ACs are the same at Autozone and the manager assured me they were (without checking) they are in fact different sizes. So I put the original back in and tightened it up, hoping maybe it had just worked loose.

Pulled a vacuum again for a bit. Then decided to deal with this problem I had of attaching the new-style r134a cans (with a self-sealing valve rather than puncture-type). The geniuses at Autozone sold me an adapter to fit the cans for use with a puncture-style filler. I have an old puncture-style filler/gauge, but obviously it would be better to fill through the yellow hose on the manifold gauge set. Of course, Autozone doesn't sell the correct adapter. Advance Auto does, but when I drove to the nearest store after checking online and seeing it "in stock" they didn't have it in stock. The next nearest store had one so I called from my truck to see if they actually had one. I gave her the part number and she told me I just called asking about it. What? Then she asked me if my name was "Don." No, my name isn't Don and I didn't just call. Do you have one or not? haha. She said someone else had just called asking about that adapter and had asked her to hold the only one they have in stock for them. haha. So I drove home and check stock everywhere online. The only place showing inventory is all the way across town, an hour-and-a-half roundtrip. I call to make sure they have it, they do (he's holding it in his hand), so I set off across town.

Meanwhile, I yesterday finished replacing the drums, shoes and hardware in both my rear wheels. I had to order a Rear Parking Brake cable as the one that was in there was the wrong size (for heavy-duty suspension maybe?). Anyway, so those drums were a TIGHT FIT, even with the spreader dialed all the way down. I was pretty sure they were in decent shape for driving, but wasn't sure I wanted to be driving at Interstate speeds for an hour because I wasn't sure how much heat might build up. Anyway, they weren't making noise or anything, just a little tiny bit of drag. So I drove on regular streets all the way over there. Oh, and it was 93-degrees here today and of course it was humid. At least I have the new stereo in my truck so I didn't have to listen to the wind blowing through the open windows.

Got the part, drove home, checked the vacuum, still holding, pulled vacuum again for another half hour or so, hooked up the can to the adapter, weighed it, let a little r134a into both sides with engine off (a very little- no waiting for both sides to equalize or whatever that means from the original op), started the truck and began filling. The compressor didn't kick on for a bit even though the low pressure was running pretty high. After 16-oz. or so was added the compressor began running. I was pretty excited about this as if you read the original post I had wondered if I destroyed my new AC system. So everything went good pretty much from there. I used a kitchen scale to weigh out how much refrigerant I was putting in (spec for my 1998 is 30oz.) and lucked out to get it right at 30.00 oz. Cold air blowing thorough the vents. Pressures looked pretty good; they mostly sat at these levels after bouncing around earlier in the process. The one concern I had was that the thermometer I used at the vent was only showing about 60-degrees, but this was possibly due to the crappy thermometer I used or the fact that sun was shining on it too.

27920


Checked just a little while ago and AC is still working good. Working so good I could only leave the blower on level 1 as it was getting too cold even though it's still near 80-degrees and humid outside. So now it's just a question of if it will continue to hold pressure. I'm a little reluctant to check as I did have those problems with that valve, so I might just see how it holds up for a bit. Thanks again to those who offered some help. Unfortunately this was the type of project and I had the sort of problems that I mostly just had to muddle through and figure out on my own.
 


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